Apparatus for driving and clinching a two-prong fastener



A. WINKLER ET AL 2,881,438 APPARATUS FOR DRIVING AND CLINCHING April14-, 1959 A TWO-PRONG FASTENER v 4 Sheets-Sheet 1 Filed Aug. 1, 1956April 14, 1959 A, 1.. WINKLER ET AL 2,831,438

APPARATUS FOR DRIVING AND CLINCHING A TWO-PRONG FASTENER Filed Aug. 1,1956 4 Sheets-Sheet 2 A w- H zivmvrons n J g aslii OldJm/rm \m'uiwm'Pawn;

Aprll 14, 1959 A. L. WINKLER ET AL 2,881,438

APPARATUS FOR DRIVING AND CLINCHING A TWO-PRONG FASTENER Filed Aug. 1,1956 4 Sheets-Sheet 5 F1. .b- 2&9 I 58 A M VENTORS 108 mu m 9 2mm April14, 1959 A, 1.. WINKLER ET AL APPARATUS FOR DRIVING AND, CLINCHING ATWO-PRONG FASTENER Filed Aug. 1, 1956 4 Sheets-Sheet 4 1 .13 1 .14 1 1.15, 59 {a (iNVENTORS United States Patent APPARATUS FOR DRIVING ANDCLINCHING A TWO-PRONG FASTENER Alvin L. Winkler and Leslie J Oldham,Chicago, 11L, assignors to Auto Stapler Corporation, Chicago, 111., acorporation of Delaware Application August 1, 1956, Serial No. 601,457

8 Claims. (Cl. 1-3) This invention relates to the art of two prong paperfasteners and particularly to a machine for driving and clinching them.

The ordinary T-shaped two prong paper fastener, as widely used today, isdesigned especially for manual use, and there seem to be no suchfasteners available on the market which are adapted or designed for usewith a machine for driving and clinching them, nor any machines. It isthe principal objectof this invention to provide a T- shaped two prongpaper fastener with an improved shape adapting it for use with a machinefor automatically driving and clinching it.

The usual T-shaped two prong fastener is ordinarily provided with itstwo prongs orlegs closely adjacent to each other, and even thoughspreading these prongs to clinch them after passing them through thepaper sheets to be fastened together can be accomplished readily by handby having one prong longer than the other, a problem arises in regard tospreading the prongs by mechanism associated with a machine for drivingand clinching the fasteners. It is, therefore, another object of theinvention to provide an improved fastener having an improved shaped headwhich, when squeezed, causes the fastener prongs to diverge or spreadapart to especially adapt the fastener for use with a machine forautomatically driving and clinching it by means of relatively simplemechanism.

It is still another object to provide an automatic machine for drivingand clinching the improved fastener, which machine is initiated by thepresence of the paper or material to be fastened and thereafterindependently completes the job of driving and clinching the fastener.

The invention can be better understood by referring to the accompanyingdrawings, in which:

Figure 1 shows a side elevation of a preferred embodiment of the machineembodying the apparatus for driving and clinching the improved fastener;

Fig. 2 shows a left end view of the machine shown in Fig. 1;

Fig. 3 shows a right end view of the machine shown in Fig. 2; 1

Fig. 4 shows a simplified schematic wiring diagram of the electricaloperating circuit of the machine;

Fig. 5 shows a preferred embodiment of the improved fastener used withthis invention;

Fig. 6 shows a sectional view of'the machine as viewed along the line 66of Fig.3 with'all of the operating parts in positions corresponding tothe start of an operat ing cycle of the machine; I

Fig-7 is identical in cross-section to the view in Fig. 6 except thatall parts are shown as they are positioned at the end of an operatingstroke of the machine;

Fig. 8 shows a sectional view of the machine as viewed along line 8-8 ofFig. 6;

Fig. 9 shows a sectional view'similar to the views of Fig. 6 and Fig. 7except that the operating parts are shown in intermediate positions.after driving of the fas- 2,881,438 Patented Apr. 14, 1959 2 tener hasbeen completed but before spreading an clinching of the fastener legshas occurred;

Figs. 10 through 15 show schematically the entire operating sequence ofall of the operations of the machine when it performs an entireoperating cycle to drive and clinch a fastener;

Fig. 16 shows a sectional view along the line 16-16 of Fig. 6. v

The improved fastener 76 for use in the improved machine, as will bedescribed, is shown particularly in Fig. 5 and consists of a head member109 connected to two legs or prongs 110 and 111 which abut each otherand-extend at right angles to the head 109. The lower ends 112 and 113of these prongs are tapered to points to permit easy penetration ofthese prong through the work material and one of the ends 113 terminatesshort of the end 112. For use on the machine, it is not necessary thatthese legs be of difierent length, but it is preferred to manufacturethem this way in order to permit manual separation of the prongs or legswith little difiiculty in cases where the fasteners are manuallyfastened. The machine, in most cases, would probably be used to providethe initial fastening of the first couple of sheets of paper which mightbe some form of stacked sheets to be circulated and the fasteners wouldbe manually opened and closed to permit subtraction or addition ofpapers to the stack during subsequent handling of the papers.

The head member 109 of the fastener is provided with a single top piece114 extending parallel to two lower pieces 115 and 116 spaced from thetop pieces 114. The outer ends of the top piece 114 and the lower pieces115 and 116 are connected by radius portions 117 and 118. The inner endsof the pieces 115 and 116 join to two members 119 and 120 which extendangularly upward toward each other and toward the top piece 114 wherethey terminate in contact with the top piece 114 and at corners 121 and122 Where they connect to the upper ends 123 and 124 of legs 110 and111. The advantage of this head member 109 is that, when the bottompieces 115 and 116 are squeezed into proximity with the top piece 114,the angles 125 provided between the members 119, 120 and the top piece114 decrease with the result that the legs 110 and 111 spreaddivergently about the corners 121 and 122 as approximate pivot points.

As shown in Figs. 1, 2 and 3, a preferred embodiment of the machine fordriving and clinching the improved fasteners 76 comprises a rectangularbase plate 1 provided with two vertically upright supports 2 and 3mounted at the corners on one end of the 'base plate 1 and a somewhatlarger vertical support 4 mounted closer to its other end. Positioned atthe upper ends of the supports 2, 3 and 4 is a top plate 5.

The support 4 is provided with two legs 6 and 7 which extend for itsentire length and are connected together by a web 8 for their upper halfand spaced apart at their lower halves for a space equal to the width ofthe web 8. This web 8 provides two grooves 9 and 10 (Fig. 16) eachprovided with bottom Walls 11 and 12, respectively, and side walls 13,14 and 15, 16, respectively. The clincher bar 17 is guided in the groove9 while the driver bar 18 is guided in the groove 10. Retainer plates 19are fastened by means of screws 20 to the support 4 and they overhangthe groove 9 in order to retain the clincher bar 17 in position in thegroove 9. Similarly, retainer plates 21 are provided on the oppositeside of the support 4 and are held in place by means of screws 22. Theseretainer plates 21 overhang the groove 10 in order to retain the IQWQIZend. of the linkv 2.6.. ispivoted on a. pin 28 to the outer end of alink 29 whose inner end is keyed to a shaft 30. The shaft 30 is mountedthrough a hole in a block 31 \vhichis fastened tothe inner face of theleg 6 of the support 4. The end of the shaft 30 opposite to that whichis-tconnected to thelink 29 is provided with a sprocket 32., aspring;33, and flange 34 and a circular cam 35, in that order. The sprocket 32is provided with one end of a chain 36 wrapped on it for aboutthree-quarters of its circumference and; engaged by the teeth of thesprocket 32. The other end of the chain 36 is connected by a pin-37 mthe plunger 38 of a solenoid 39. The, solenoid 39 is: mounted on thebase plate 1. The spring-33 is a coil spring with one end fastened tothe shaft 30 by means of a pin 40.. Its other end-41 reacts against theupper surface of the. base plate 1. The spring is positioned so astotendto rotate the shaft 30 in clockwise direction as viewed in Fig. l.The cam is circular except for a detent; 42 at one small portion of itsperipheral circumference.

A. switch 43 is mounted on the base plate 1 and pro vided with: avplunger fitted with a roller 44 which is always in contact with theperiphery 44 of the cam 35. When the cam 35 is rotated to a point wherethe roller 45 drops into or out of the detent 42, the switch 43 isactuated.. Its operation will be discussed in more detail in connectionwith the entire electrical operation of the machine.

The clincher bar 17 is connected at its upper end to the lower end 46 ofa C-shaped clincher arm 47 whose upper end.,.48. extends inwardly acrossthe path of travel of the driver bar 18. Its. under surface 49 is itsclinching surface. The end 48. is considerably wider than the rest ofthe-clincher arm 47 and extends beyond the inner edges of the twovertical support members 50 and 51.

The upper end 48 of this clincher arm 47 is provided with an aperture 52having an inclined front inner surface 53.

The support members 50 and 51 are spaced apart from each other andfastened at their lower ends by means of screws 54 and 55 to the upperportion of the arms 6 and 7 of' the support 4. The upper ends of thesesupport members. 50 and 51 are provided with inwardly extending lugs 56'which provide bearings for supporting the two ends of a shaft 57. Theshaft 57 supports, atits midportion, anauxiliary. clincher 61 having adownwardly extending arm passing through the aperture 52. of theclincher arm 47 and consisting of a straight portion 53 connectedto aportion 59 extending angularly forward which in turn connects to anotherstraight portion 60 whose lower end'terminates the auxiliary clincher61. A-coil spring 61a is mounted concentrically with the shaft57 to urgethe lower end of the auxiliary clincher 61 forward. The extreme lowerendv of the portion 60-is provided with an angularly sloped back 62 forpurposes ofclearance while its front surface is provided with twotriangular shaped. and. pointed ends 63 and 64 having adjacent sideswhich extend divergently upward. The auxiliary clincher 61' is usedduring an intermediate step beforefinalclinching of the fastener prongsto act as a backing to permit initial spreading of the fastener prongsaway from each other. This operation will be discussed inmore detailalong with the discussion of the entire operation ofv the machine.

The clincher bar 17 is provided with two spaced lugs 85 projectingdownwardly from beneath the clincher arm 47'. These lugs 85 support apin 86 between them and the upper end 87 of an L-shaped link 88 ispivoted on the pin- 86. The lower end 89 of the link 88 is pivoted onapin'90 tothe outer'end of another link 91 whose inner end is keyed tothe inner end of a shaft 92 which in turn is=trunnioned in a hole 93:passing through the leg 7 of the support '4." The outer end of the shaft92 isprovided, in this-order; with a chain sprocket 94, a coilspring 95mounted o na flanged hub 96 keyed to the shaft 92, and a circular cam 97provided with a circular periphery 98 having a detent 99 (Fig. 6) Thisarrangement on the outer end of the shaft 92 isi similar to thearrangement of parts on the shaft 30 which is associated with the driverbar operating mechanism. The sprocket pinion 94 is provided with a chain100 which is wrapped partially around the sprocket at its outer end andits inner end is secured to the plunger'101 of a solenoid 102. Thespring 95 has oneend secured to a pin 103 mounted in a fixed positionrelative to the shaft 92. and its outer. end 104 reacts against the,upper surface of. the base plate 1. The effect of this springarrangementisto tend to urge rotation of the shaft 92 in acounter-clockwise direction, as viewed in Fig; 1. Thecircular cam 97 isassociated with a switch 105 which is provided with a roller 106 whichis always in contact with the peripheral surface 98 of the cam 97. Theswitch 105 is actuated as the plunger either engages or disengages thedetent 99 provided on the cam 97. V 7

As shown best in Figs. 6, 7, 8 and 9', a flat leaf spring 65 has. itsrear end mounted on a crosspie'ce. 66and1it is held inplace, by means.of two screws 67 which fasten the end of the springto; thecrosspiece 66by meansofa retainer plate 68.. A central portion of the springisprovided with an aperture, 69 through whichthe clincher arm 47 passes.The forward end of the spring is provided with an inwardly extendingslot 70 which is aligned with the path of travel of thefdriver bar 18and, likewise,,the path of travel'of a fastener to be driven. When afastener is drivenby the driverbar 18,, its two. closely positionedprongs pass through the slot 70'andthe spring is used as a guide totemporarily hold the fastener after itslegs. are spread, but beforefinalflclinching. It is also. used as a backingin caseseveral slieets.of paper to be fastened together provide too much cushion to permitadequate compression of the fastener head. The. slot 70of' thespring 65is providedwith inwardly tapered sidewalls 70a ('Fig. 8) .which leadinthe fastener subsequent to the one being driven as the spring drops backdown after a fastening cycle has been completed.

As shown in Figs. 1 2, 3, 6, 7, 8 and 9, a fastener magazine 71 isfastened to the lower surface of the top plate. 5 by means of screws 72.which pass through: outwardly extending flanges 73 of'the magazine 71,.The magazine is provided with twovcrtical side walls 74 spaced-from eachother sufficiently to provide anv opening for the. legs, of a fastener.These walls 74 connect at their lower ends to two laterally extendingchannels having upper and bottom Wall's spaced'from each-othersufficiently to permit the passage of the heads of the fasteners, Thefasteners 76 are positioned abutting each other. in. acontinuous row, asshown in Figs. 6, 7, 8 and 9, within the magazine 71, andthe forward end77of the plate 78 presses. against the outermost fastener to keep thefasteners closely positioned to each other. pl'a't'e78 is providedat itsouter end with a pin 79 fastened'to the end of a long helical spring 84whose forward portions are coiled about 'a'pin 82 with the leading'endof the spring securely fastened to the pin 82. Thepin 82 is mounted in abracket 83 suspendedfr'om thelower portion of the magazine 71. Thespring84'is used to cause the plate 78 to'be pressed forward against theoutermost fastener as already described. V

Another switch-107'ismounted on the outer edge of the leg6 of thesupport 4'and'it is providedwith an outwardly extending arm 108 whichprojects abovethe upper level of the top plates. The switch 107isactuated b'y'movement'of this arm 108'. The arm 108 ismoved by-contactwith. the leadi'ng edge of a paper or"pape'rs tobe fastened when theoperator feeds the papers to the machine;

In Figs. 10 through 15 are shownthe sequential opv crating movements ofthe machine. Initially; a fastener 76 rests with; its. headz109xupon:vthe: upper end 23 of the driver bar.18;'therfastener'having beensupplied fromathe magazine 71. The legs of the fastenerprotrudeupwardlyi through slot 70 of the spring 65. Above the spring 65are positioned the papers 126 which are to be fastened together. Abovethe papers are positioned the points 63 and 64 of the auxiliary clincher61. Theupper end 48 of the clincher arm 47 is provided well above thetips 63 and 64 of the auxiliary clincher 61. As shown in Fig. 11, thefirst movement of the machine is the operation of the driver bar 18which drives the fastener 76 upwardly so that its head deflects thefront end of the spring 65 upwardly into contact with the paper throughwhich passes its legs. The legs 110 and 111 end up positioned betweenthe tips 63 and 64. Next, as shown in Fig. 12, the driver bar 18continues upwardly to squeeze the head 109 of the fastener 76 againstthe lower surfaces of the tips 63 and 64. This decreases the angularrelationship 125 of the portions 119 and 120, as already describedrelative to Fig. 5, with the result that the legs 110 and 111 spreadangularly apart. As shown in Fig. 13, after the legs are spread in thismanner, the upper end of the clincher arm 48 is moved downwardly so thatits lower surface 49, contacts the fastener legs and causes them to befinally clinched as shown in Fig. 14. During the movement shown in Fig.13, the auxiliary clincher 61 is cammed out of the path of the fastenerby the clincher arm 47 as its wall 53 cams against the angular portion59 of the auxiliary clincher 61. This camming action clears the path ofthe tips 63 and 64 for the upper end 48 of the clincher arm 47, so thatit can complete the clinch, as shown in Fig. 14, to cause the fastenerlegs 110 and 111 to extend parallel to the head member 109. Afterclinching has been completed, the driver bar 18 and the clincher arm 48are returned to their initial positions and the auxiliary clincher 61again projects its ends 63 and 64 into the path of travel of a fastenerbecause of its spring return. As shown in Fig. 15, the spring 65 isstill positioned between the head of the fastener and the paper sheets.In order to remove the spring from the clinched fastener, it is mere--1y necessary to pull the paper out of the machine. Note that the spring65 is needed during the movement of the clincher arm 47 which isindicated by the movement of its upper end 48 in Fig. 13. At this time,since the auxiliary clincher 61 has been removed, without the spring 65present there is the possibility that the fastener being clinched mightbecome misaligned.

In order to acquire movement of the driver bar 18 for the purpose asdescribed, the solenoid 102 is energized to cause its plunger 101 topull the chain 100 to cause rotation of the 'shaft 30 with a resultantmovement of the link 26 to cause the driver bar to raise vertically.Upon completion of the driver stroke and when it is necessary to returnit to its initial position, the solenoid 102 is de-energized so that thespring 33 causes reverse rotation of the shaft 30 to return the link 26andthe driver bar 18 to its initial position.

When it is desired to lower the clincher arm 47 for the purposedescribed, the solenoid 39 is energized to cause its plunger 38 to pullthe chain 100 and cause rotation of the shaft'92 to cause the link 88 tolower and cause the clincher bar 17 to be lowered. At a time when theclincher bar 17 is again to be raised to its initial position, thesolenoid 39 is de-energized and the spring 95 causes reverse rotation ofthe shaft 92 to return all parts.

As shown in Fig. 6, the parts are all positioned to correspond to thelocation of parts shown in Fig. at the beginning of a fasteningoperation. Fig. 9 represents the position of parts corresponding to theparts as shown in Fig. 11, while Fig. 7 shows the positions of partscorresponding to the positions shown in Fig. 14 at the completion of adriving and clinching operation. Note in Fig. 7 that the clincher arm 47is retracted to a position where its clinching surface 49 is below thelevel of the lower surfaces of the tips 63 and 64. This happens becauselink 29 has rotated past center to cause slight retraction of the driverbar 18 to a position lower than that shown in Fig.

9 and the clincher arm 47 has lowered to the correspond- 'ing lowerposition of the driver bar 18. In Fig. 7, the

driver bar 18 is in a position of squeezing of the fastener head 109 toreact against the tips 63 and 64 to cause divergence of the legs 110 and111. The driver bar 18 is retracted as mentioned in order to relieve thesqueezing force and permit the tips 63 and 64 to be easily retracted asthe clinching arm 47 moves downwardly and earns against them. I

The electrical operation of the machine can be understood by referringto' the simplified electrical diagram shown in Fig. 4. The voltage isprovided through a plug 133 between wires 134 and 135. These wires 134and 135 are provided with two branch circuits. The first branch circuitconsists of switch 107, relay switch 131 and the solenoid of relay 130connected in series between wires 134 and 135. The second branchconsists of switch 43, the solenoid 102, relay switch 132 and two poles105a and 105b of the switch 105 connected in series between wires 134and 135. An additional solenoid 39 is connected from one of these branchcircuits to the other at points between switch 107 and relay switch 131,and solenoid 102 and relay switch 132. Another contact 1050 of theswitch 105 connects between relay switch 131 and the solenoid of therelay 130.

Prior to the start of an operating cycle, voltage is supplied across thewires 134 and 135, all electrical parts are de-energized, and the partsare in the positions as shown in Figs. 1, 2, 3,4 and 10. The openswitches are 43, 107 and 131. A closed switch is 132 and switch 105 hasits contact 105a connected to its contact 105b. The solenoids39, 102 andthat of relay 130 are all de-energized.

' When a paper or papers are inserted into the machine, the

paper contacts the arm 1080f the switch 107 to cause this switch 107 toclose. This in turn energizes solenoid 39 by supplying electricalcurrent through switch 107, the solenoid 39, closed switch 132 and thecontacts 105a and 105b of the switch 105. With solenoid 39 energized,its plunger 38 is retracted to cause rotation of the shaft 30 withconsequent upward driving of the driver bar 18 to cause the fastener topenetrate the paper and have its legs spread as the head 109 of thefastener is squeezed against the lower surfaces of the point ends 63 and64 of the auxiliary clincher 61. At this time, as already mentioned, theend of the spring 65 is also raised up against the paper to act as aguide and retainer for the fastener. As also mentioned, it is also usedas a backing especially helpful when several sheets of paper to befastened together provide too much of a cushion to permit adequatecompression of the head 108 of the fastener.

Immediately upon completion of the driving stroke, the cam 35 hasrotated sufliciently so that the roller 44 of the switch 43 drops in the.detent 42 of the cam 35 and causes the switch 43 to close. At this timesolenoid 102 is energized as current passes through the switch 43, thesolenoid 102, the closed switch 132 and the contact 105a and 105b of theswitch 105. Energizing switch 102 causes the plunger 101 to be retractedto cause the chain to rotate the shaft 92 and thereby lower the link 88and the clincher bar 17. This causes the upper arm 48 of the clincher 47to be lowered down against the paper and cause final clinching of thelegs of the fastener. This action occurs by the motions indicated inFigs. 13 and 14. When clinching has been completed, cam 97 has beenrotated to a point where the roller 106 of the switch falls into thedetent 99 on the cam 97. This causes the switch 105 to change positionsso that contact 105a breaks with contact 105b and connects with 1050.This causes energization of the solenoid of the relay 130. Energizingthis solenoid causes its relay switches 131 and 132 to be alternatelyopened and closed. Switch 131 closes while switch 132 opens. Openingswitch 132 causes de-energization of both solenoids 39 and 102 to permitreturn of the clincher bar 17, the driver bar 18 and all related partsbecause of the spring return 'actionof' thetwo spring's and 95'; Closingswitch 131 merely keeps the solenoid of the relay- 130 energized at thistime. when the-paper. is removedfrom the machine, switch 107 is'openedto de-energize the coil of the relay 130 to in turn cause closing ofswitch 132 and opening of switch 131. This leaves the machine in itsinitial electrical condition ready for a new cycle of operation.

Although one form of fastener and machine have been shown and describedparticularly, it' will-be obvious to persons skilled in the artthatother constructions and modifications are possible without departingfrom the true scope of the appended claims defining the invention.

We claim: 7

l. A machine for applying fastener of a type characterized by a headconnected to the upper ends of two prongs which diverge when the .headis squeezed, comprising means for drivingthefastener through a workpiece, means for squeezing the head to cause the two prongs to diverge,and means" for clinching the two prongs against the work piece.

2. A machine for applyin'g a fastener of a type having a head connectedto two prongs; said head being provided with upper andlower bars, saidlower bars having portions extending angularly toward each other toconverge at a juncture with the upper ends of said prongs adjacent saidupper bar, comprising means for driving the fastener head into contactwith and squeezing it against an intermediate clincher to compress said'head and cause the angular'portion of said lower bars to flatten and theprongs to diverge.

3. A machine for applying a fastener of a type having a head connectedto two prongs, comprisingmeans on one side of a work piece for drivingthe fastener to cause its two prongs to penetrate the work piece, compression means on the opposite side of the work piece in the path oftravelof the fastener bar compressing the fastener head, and meansforbo'th deflecting said compression means out of the path of' travel ofthe fastener and for clinching the two fastener prongs.

4. A machine for applying a fastener of a type having a head connectedto two prongs which diverge upon compression of the head, comprisingmeans on one side of a work piece for driving the fastener to cause itstwo prongs to penetrate. the work piece, compression means on theopposite side of the work piece in the path of travel of the fastenerfor compressing the fastener head and causing divergence of 'saidprongs,and means for deflecting said compression meansclear of the path oftravel of the fastener and'for'foldingthe prongs against the" workpiece.v c v 5. A machine: for applying'a fastener of a. type having a headconnected to two prongs which diverge upon compression of the head,comprising a support for a piece to be fastened, a magazine attached tosaid support for holding a supply of fasteners for supplying fastenersto a driver reciprocably mounted on said support on one sideof'saidworkpiece, said driver causing a fastener to be displaced fromsaid magazine to cause 0 its prongs to penetrate said work piece,compression means on the opposite side of said work piece retractablymounted on said support in the path of travel of said fastener forcompressing thev fastener head and thereby causing divergence of the:prongs of said fasteners, and a clincher arm reciprocably mounted onsaid support for deflecting said compression means clear of the path oftravel of the fastener and for folding said prongs against the workpiece.

6. A machine for applying a fastener of a type having a head connectedto two prongs which diverge upon compression of the head, comprising asupport for a work piece to be fastened, a magazine attached to saidsupport for storing a supply of fasteners to be supplied one at a timeto a driver reciprocably mounted on said support, said. driver adaptedto drive a fastener supplied from said magazine to cause its two prongsto penetrate said' workpiece, compression means retractably mounted onsaid support and ordinarily biased to extend into the path of travel ofsaid fastener being driven for compressing the fastener head and therebycausing divergence of said prongs, and a clincher arm reciprocablymounted on said support for retracting said compression means clear ofthe path of travel of the fastener being driven while the clincher armtravels to fold the fastener prongs against the work piece.

7. A machine for applying a fastener of a type characterized by a headconnected to the upper ends of two prongs which diverge when the head issqueezed, comprisingmeans for driving the fastener prongs through a workpiece, means to guide the prongs while they are driven, means forsqueezing the head to cause the two prongs to diverge after theyarediiven through the work piece, and means for clinching the two prongsagainst the work piece.

8. A machine for applying a fastener of a type characterized by a headconnected to the upper ends of two prongs which diverge when the head issqueezed, comprising driving means for driving the fastener prongsthrough a work piece, retractable compression means for squeezing thehead against the driving means to cause the two prongs to diverge afterthey are driven through the work piece, resilient means to both guidethe prongs while they are driven and to support the fastener after thecompression means is retracted, and means for clinching the two prongsagainst the work piece.

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